Chain drive



Patented Dec. 26, 1939 UNITED STATEE ATEiiiT OFlfiE CHAIN DRIVE Application January 10, 1939, Serial No. 250,227

5 Claims.

This invention relates to improvements in driving connections between chain operated sprocket gears and pertains particularly to an improved means for permitting relative movement of such gears The primary object of the present invention is to provide a new and novel means for tensioning the drive chain between chain connected sprocket gears whereby such chain may be maintained taut at all times while at the same time permitting a relative movement between the gears which it operatively couples together, where such gears are connected with adjacent or contacting units which at times may be forced apart by material passing therebetween.

' While it is to be understood that the present invention is not to be confined to the specific type of mechanism for which it has been designed, it is shown in association with feed rolls which are employed in textile machinery for holdingstock, such as wool, cotton and other fibrous material, which is to be delivered to the opening cylinder of the machine. In machines of this character, the feed rolls heretofore were connected and driven by spur gears and when such rolls separated in the course of the passage of material therebetween, the driving connection between the gears was interrupted due to the partial or complete disengagement of the teeth of the gears. With the present driving mechanism for such rolls, means is provided which permits the top roll or rolls to raise any amount necessary without retarding the rotation of the rolls while at the same time maintaining the driving chain between the rolls taut.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming part of this specification, with the understanding, however, that the invention is not to be confined to any strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the sa- 0 lient features of the invention as expressed in the appended claims.

In the drawing:

Fig. 1 is a view in elevation of the chain drive embodying the present invention.

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a View illustrating a modification oi the structure shown in Figs. 1 and 2 for application to a single pair of sprocket gears.

Referring now more particularly to the draw- (Cl. M -223) tration of the present invention it is only necessary, in order to disclose the invention, to show one side of the frame structure supporting the drive rolls at one end and, therefore, no detailed illustration has been made of the said rolls or of any of the other parts as these parts form no part of the present invention.

The frame structure I consists of the two spaced standards 2 between which is disposed the central post 3. The standards 2 and the post 3 may be formed integral with a base portion 4, as shown, or secured in any other suitable manner to a supporting bottom unit, while thetop ends are connected by a cap or head bar 5, such cap being secured in the usual manner by the nuts 6 at the ends thereof, which pass downinto the upper ends of the standards 2. Eachof'the standards 2 forms with the adjacent post 3 a guide for upper and lower roll shaft supporting bearings I and 8, respectively. These bearings receive the ends of shafts 9 and III which, when the invention is used in association with a machine of the character previously stated, may support the feed rolls for the machine.

There are thus provided two bearing guides,

each of which is indicated by the numeral 'I I, so' that there are provided the two sets of superposed shafts and bearing blocks.

The lower blocks 8 are held in place in the g ide area by a fixed member I2 while each of the upper bearing blocks is flanged, as shown, so that it may have vertical sliding movement within the guide area. The top of each shifting or sliding bearing block carries a stud I3 which is directed upwardly and in opposed relation with this stud and in the upper part of the guide area is a spring follower I4 having a downwardly directed stud l5, and this follower is held for vertical adjustment in the guide by the tension bolt I6 which is threaded through the cap in the manner shown. Interposed between each follower 94 and the underlying sliding bearing block is a spring I! in the upper and lower ends of which the studs I5 and I3, respectively, engage, this spring constantly exerting a downward pressure against the underlying sliding bearing block so as to maintain the two superposed blocks in operative relation. i

Adjacent the upper part of each standard,

there is secured to the side thereof which is away from the center post, a bracket I8 which carries a pivot stud Hi. This stud I9 passes through and oscillatably supports a lever 20 which is formed to provide a bearing 2! located at a point intermediate its ends so that it will lie with its center substantially in the plane of the centers of the underlying bearings 1 and 8.

The shafts 9 and i0 carry sprocket gears 22 and 23, respectively, and secured in the bearing opening 2| of the overlying lever is a stud 24 for an idler sprocket 25.

The free ends of the levers 20 come into opposed relation at the center of the post 3 and their opposed end faces are provided with notches 26 to receive between them the lower end of a spring controlled tension bolt 21. This bolt 21 is slidably held in the guide bracket 28 which is secured to the cap 5 and above the guide bracket, the tension bolt is encircled by an expansion spring 29 which engages against an adjusting nut 30 and normally operates to pull up on the bolt so as to maintain the inner ends of the levers 20 at their highest positions.

The upward movement of the levers 20 which carry the idler sprockets 25, is limited by the endless sprocket chain 3l which extends across the tops of the idler sprockets and down over the outer sides thereof, passing downwardly and inwardly across the inner sides of the sprockets 22 which are supported by those shafts which are carried by the sliding bearing blocks, then passing downwardly and outwardly around the outer sides of and beneath the lower fixed sprockets 23.

From the foregoing, it will be readily seen that with the drive connection here shown, between the movable and stationary sprocket gears of the superposed shafts, the upper ones of the said shafts may shift against the tension of the springs I1 without disturbing the driving connection between the adjacent gears. When such shifting or raising of the upper shafts 9 occurs, the associated gears will merely roll on the contacting runs of the sprocket chain and any pull or strain which may be applied to the chains will be compensated for by the yielding of the spring 29 to allow the idler sprocket carrying levers to move down. As soon as the tension upon the sprocket chain is released, the spring 29 of the tension bolt will expand and pull upwardly on the bolt and thus tighten the chain. Thus it will be seen that with the drive here described, a considerable amount of movement of the upper one of the shafts may take place without in any way interfering with the rotation of or driving connection between the shafts.

While the foregoing description has been applied to a double set of shafts and rolls, that is, two sets in each of which there is a fixed bottom roll and a movable upper roll, the tensioning mechanism may also be employed in association with a single pair or set of rolls. Such mechathem for use in connection with a single pair of rolls and sprocket gears is illustrated in Fig. 3, wherein there are shown the two standards 3! between the lower ends of which are the bearings 32 and 33, the bearing 33 being above the bearing 32 and adapted to move vertically between the standards 3! against the tension of the controlling spring 35. This spring is normally held down by the vertically adjustable tensioning screw 35 in the manner illustrated.

In this form of the invention, one of the standards 3! is provided with a suitable ear 36 which carries a pivot pin 31 with which one end of a lever 38 is pivotally connected. This lever extends across the standards in the same manner as the levers 20 and upon the opposite side of the standards from the pivot 31 is engaged at its respect to the lower sprocket gear with the hear ing 33 and against the tension of the spring 34. A sprocket chain '45 passes over the idler sprocket gear ll and connects the same with the two sprocket gears 42 and 43 in the manner illustrated, one run of the chain passing across two opposite sides of the smaller gears and around the under one thereof to form the opposite run which leads back to the idler gear. With this arrangement, it will be readily seen that exactly the same action is obtained as is obtained with the structure shown in Figs. 1 and 2, in that the spring 39, like the spring 29, acts constantly to tension or hold the sprocket chain taut andat the same time a freedom of action'is allowed for the movable bearing 33 which permits the bearing and the shaft passing therethrough to shift with respect to the underlying bearing and the shaft which it supports.

What is claimed is: s

i. In a chain drive of the character described, a pair of sprocket wheels and an idler sprocket, said sprockets being all in a common plane of rotation and spaced in alined relation, means supporting one of said sprocket wheels whereby the same may move between the other sprockets, a second idler sprocket disposed in said plane and adjacent to and laterally of the first idler sprocket, a sprocket chain having a run passing across the two idler sprockets and passing from one idler sprocket to and across opposite sides of the sprocket Wheels whereby said wheels are oppositely rotated, movable supporting means for the two idler sprockets, and means common to said supporting means and said idler sprockets normally urging said movement of the idler sprockets in a direction away from the sprocket wheels to effect tensioning of the connecting chain.

2. In achain drive of the character described, a pair of sprocket wheels and an idler sprocket, said sprockets being all in a common plane of rotation and spaced alined relation, means supporting one of said sprocket wheels whereby the same may move between the other sprockets, a second idler sprocket disposed in said plane and adjacent to and laterally of the first idler sprocket, a sprocket chain having a run passing across the two idler sprockets and passing from one idler sprocket to and across opposite sides of the 1 sprocket wheels whereby said wheels are oppositely rotated, a pair of pivotally mounted levers each having one of said idler sprockets rotatably supported thereon, and resiliently controlled adjustable means common to and connected with rotatable units each in superposed relation with one of the first-mentioned units and each having a sprocket wheel connected therewith, the second-mentioned rotatable units and the sprocket wheels connected therewith being supported for movement in a fixed path relative to the firstmentioned rotatable units, a pair of levers, pivotal means supporting each of said levers at one end for oscillation in paths perpendicular to the rotary axes of said units, an idler sprocket rotatably supported upon each lever and in the path of the two superposed units, a sprocket chain common to and connecting all of said sprocket wheels and idler sprockets, said chain passing across and over the outer sides of the idler sprockets and passing inwardly across the inner sides of the movable sprocket wheels and passing outwardly across the outer sides of and connecting the remaining sprocket wheels whereby the movable sprocket wheels will be rotated oppositely to the first mentioned sprocket wheels and adjustable means resiliently urging said levers away from the sprocket wheels whereby the connecting sprocket chain Will be constantly maintained taut.

4. In a mechanism of the character described, means providing a pair of elongated parallel guide areas, a fixed bearing in one end of each of said areas, a shaft connected at one end in each of said bearings, a sprocket wheel secured to each shaft, a sliding bearing in each area adjacent the fixed bearing and supporting an end of a shaft, a sprocket secured to each shaft of a sliding bearing, a lever pivotally supported at one end at the outer side of each of said areas and extending across the area, the said levers having their other ends in opposed relation, an

idler sprocket rotatably supported upon each lever, a sprocket chain common to and connecting together all of the sprocket wheels and idler sprockets wherebythe movable sprocket wheels will be rotated oppositely to the adjacent fixed sprocket wheels and said movable sprocket wheels may shift between an idler sprocket and the adjacent fixed sprocket wheel, a bolt member loosely connected to and between the ends of said levers, and spring means connected with said bolt and normally urging the same in a direction to shift the levers away from said sprocket wheels whereby to tension said sprocket chains.

5. A mechanism of the character. described, comprising a pair of shaft carried sprocket gears arranged in superposed relation, a pair of spaced parallel bearing guides, supporting bearings for the shafts carrying the gears, the bearing supporting the upper one of the superposed gears being slidably supported between said guides to shift relative to the lower gear, a straight lever arm pivotally supported at one end upon one guide above said gears and extending across the space between the guides, an idler sprocket gear supported by said lever between its ends substantially in alinement with the said superposed gears, resilient means operatively coupled between the other end of said lever and a guide and normally urging the movement of the lever away from the said sprocket gears, and a sprocket chain coupling all of said gears together, said chain having one side run thereof passing across opposite sides of the pair of sprocket gears.

ISAAC L. HALL. 

